Understanding why chemotherapy is used so widely against cancer in spite of its side effects requires a bit of information about how the cells in your body grow and replicate. The cells in the normal tissues in your body are usually in the “resting phase” – they will not divide into more cells any more as they are programmed to remain in this state. However, the cells in cancerous tissues are more often in a “replication phase” – they are dividing themselves into more cells. They don’t do it faster contrary to popular belief, it’s just that more cells are dividing than usual. The aim of chemotherapy is to attack this difference between normal cells and cancer cells: the state in which the cells remain.
II. What is chemo then??
Chemotherapy refers to a drug or a group of drugs which attack cells in their “replication phase”. They are not given in a targeted manner like radiation but taken either by mouth or as an intravenous drip. The downside of this method is that the entire body is exposed to chemotherapy drugs. We mentioned before that the majority of cells in normal tissue are in the “resting phase”. However, the human body does have areas like hair follicles, skin, gut, and bone marrow which also divide rapidly (this is a part of their normal process). These are the areas that are the collateral damage in the war against cancer that chemo wages.
Because of these side effects, chemotherapy is usually given as a combination of drugs at the maximum tolerable doses. The combination differs for different cancers and the dose is calculated on the basis of a person’s body surface area (which depends on their height and weight).
III. What does a chemo regimen look like?
Remember we said chemo drugs are usually given in combination rather than as a single drug? Chemo drug regimens refer to the details: the specific drugs that are used, at what dose, how often will the drugs be given, and for what duration.
The chemo drug regimen is divided into cycles – usually each cycle includes a certain period of taking drugs, followed by a period of rest. This pattern is then repeated for the number of cycles specific to the chemo regimen.
Chemo drugs can either be swallowed as a pill or taken as an IV drip. When taken orally, the exact frequency and duration is specified by your doctor. However, some drugs cannot be given orally and have to be given as a drip. In these cases, often the patient is fitted with a “portacath” – a portable catheter, in the skin of any part of their body. If inserted, this tube stays in for the duration of the cycle (it may be changed if there is a medical indication that it should be) and makes it easier to give the drip as the person is not getting repeated injected. Typically, the IV part of the chemo is taken once in one or two weeks, and each session could last as little as 30 minutes to 6 hours depending on the regimen.
IV. So, all chemo is the same right??
Not all chemotherapy is the same! Depending on the type, aggressiveness, and the stage of the cancer, the type of chemotherapy can differ. They can be of the following five types:
a. Chemotherapy can be used as the primary treatment in cases where the cancer is advanced, leaving no other feasible options.
b. After removal by surgery, chemotherapy can be given as an adjunct to remove any remaining cells that might be present.
c. It could also be given before surgery to reduce the size of the cancer.
d. Chemotherapy can be given as a maintenance therapy after the initial treatment is over, to increase the clinical remission as well as prevent relapse
e. In certain tumours which do not respond to other forms of treatment, chemotherapy can be given as a stabilizing treatment to keep the tumour size small and maintain a quality of life.
V. How will chemo affect me?
Since a combination of drugs are often used in chemotherapy, it also increases the toxic effects. The effect of chemotherapy on the gut, bone marrow, and hair follicles (leading to hair loss) are responsible for majority of the side effects. The majority of the gut side effects include nausea, vomiting, loss of appetite, taste changes, diarrhoea, and constipation. The effects of chemo on the bone marrow results in anaemia, increased susceptibility to infection due to decreased white blood cells, and fatigue. It should also be noted that those who have undergone radiation therapy before chemo are more likely to be develop the side effects at a lower dose, hence the chemo doses are usually lowered for them.
VI. How can I make it better for me?
Getting chemotherapy is an essential part of cancer treatment – however, there are ways of making yourself as comfortable as is possible while undergoing chemotherapy. Many cancer patients have reported feeling different after undergoing treatment even though they may look the same. While some take time to go back to their regular schedule, others can’t wait to get back to it. Whatever you choose, you will deal with some setbacks due to the chemo: difficulty in sleeping, tiredness, depression, and pain are common symptoms. However, there are ways to help feels better. Using a balm containing essential oils before sleeping can help to calm your mind, while a cooling gel mask you place over your eyes before bedtime can relieve headaches and eye strain. Wearing hats could be a better option than a wig – which can get itchy and sweaty and there are hair products out there specifically made for the hair thinning cancer patients face after chemotherapy. The post chemo time is a time of transition – it is good for one to allow the mind and body some space and time to get used to these changes.
Williams textbook of Gynaecology, 3rd edition
Sabiston Textbook of Surgery, 17th edition
Harrison’s Principles of Internal Medicine, 19th edition